For fun, I decided to try to design a few low tech ships. I found that I could go as low as TL 7 on many of the steps, but I've ran into problems.

Low tech weapons. The only weapons I see at TL 7 are missiles and torpedoes. I'm hoping for more variety, such as firearm ships weapons. I'm trying to avoid relying on missiles being the only weapon for fighters.

No TL 7 software. Not even Manoeuvre/0 or Library. I'm wondering if the ships will be able to fly? If so, do they suffer penalties? I'm questioning whether or not to even buy a ship computer...

No TL 8 sensors. The lowest they go is TL 8.

Fission power plants. I'm not sure how much fuel they use and how much it costs. I'm expecting the numbers will be different than what is used for fusion.

Buying missiles. Do you buy missiles individually, or as a pack? What I mean to say is, is the price 250,000 Cr for a single missile or is that the price for a dozen standard missiles?

Well, if TL7 is current day, then I would say that Missiles are the only real option for a space craft. While we are experimenting with Lasers etc. they really are prototypes of TL8 weapons and may not realistically be used on a small spacecraft.

Regarding everything else that is TL8. I would suggest that you use the Prototype Rules in HG. They let you build something 1 TL early, but at a higher cost and size. Perfect for those experimental spacecraft from a TL7 society. Prototype software makes sense too. It is custom built, so is much more expensive. Even sensors could be prototypes - Radar has a pretty short range in space terms.

DivineWrath wrote: ↑
Low tech weapons. The only weapons I see at TL 7 are missiles and torpedoes. I'm hoping for more variety, such as firearm ships weapons. I'm trying to avoid relying on missiles being the only weapon for fighters.

You can use small weapons, such as auto-cannons. The range sucks, though.

DivineWrath wrote: ↑
Fission power plants. I'm not sure how much fuel they use and how much it costs. I'm expecting the numbers will be different than what is used for fusion.

There is no given cost for fissionables or antimatter, perhaps since they are not commonly available.

DivineWrath wrote: ↑
Buying missiles. Do you buy missiles individually, or as a pack? What I mean to say is, is the price 250,000 Cr for a single missile or is that the price for a dozen standard missiles?

Not released yet, but you'll see it on Drivethru before Christmas (look out for the Great Rift).

Not yet released? I'll keep an eye out for it then.

Anyways.

I'm thinking that a ship firearm like weapon would do 1D damage, would have a range of short, and cost maybe 0.25 MCr. Maybe give it the autofire trait.

How important would a shipyard be to TL 7 world? I'm trying to design a starport and I'm not sure what kind of class to make it. I was thinking class B until I saw it needed 10,000 tons minimum for the shipyard. I don't want to waste space so I'm trying to figure out how much demand there will be for TL 7 ships.

Well, I think I'm done with the TL 7 Class C starport. It is 75,000 ton station that meets the qualifications for a Class C starport in all ways except sensors and M-drive. Sensors is a still a problem as TL 7 doesn't allow for even the most basic of sensors. It has no no reaction drive because there is no rating 0 reaction drive. Maybe I should take a rating 0 M-drive and pretend its reaction drive. Other than that, I think it looks good. It has 6000 tons for a hamster wheel to simulate gravity and its used for living quarters and other stuff.

You will not hit anything that can manoeuvre at 1000 km (Short) with a cannon, but perhaps Close (~10 km), and certainly Adjacent (<1 km).

I wonder about that at times; I think it's an "implications of technology" thing. At TL7 a ship won't have fancy reactionless M-drives; every "dodge" is going to require precious reaction mass. A TL7 warship might actually have to consider "do we want to use reaction mass to dodge this or will the armor of the ship be able to handle it?" (eg; will they get a low damage roll or a high one)

We did a TL7 ship for the Great Rift (which, as a referee, you just have to get your players on!). For sensors, I will be recommending they look out of the windows...

I am assuming you're referring to the players being forced to use some low-tech kitbash in the Great Rift so there's no resources to develop sensors.

I think the idea of "low tech star travel" is a field just begging for proper treatment in MgT. A lucrative potential. Think of it fulfilling what "Hard Times" did for MegaTraveller all those decades ago.

Even in a "What if we let von Braun take us to the stars" timeline, I think sensors are possible on a starship beyond just visual inspection, especially once a civilization starts building purpose-built starships in orbit, ones that can never land on a surface without burning up on re-entry or crashing spectacularly. For instance, at lower tech levels the computing power doesn't exist for a lot of apeture sensors so you'd literally need to build a larger sensor array and stick it on a starship. While the engineering hurdles to mount a 100m wide radar dish onto a starship would be great, it is within the realm of the feasible since you don't have to worry about launching all that extra mass into orbit (it's being built in space) and there's no atmospheric drag. A pair or trio of starships might fly with a huge kilometers-wide array between them like a huge fishing net to get the apeture they need for their low-tech sensors.

Now I guess it could be argued that by the time you get all that to work you'd be at TL8 from the research but I think majority of the critical components would be at TL7. It'd be larger, bulkier, more fragile, less efficient, and much more expensive but I think you could still make sensors with a range of 10,000km at TL7. Probably even at TL6. TL5 ... maybe not.

I'm noticing you can't carry enough reaction mass to go anywhere beyond maybe to the nearest moon. I'm sure people are very happy with the initial discovery of maneuver technology just to explore their own star system. I bit like what we're experiencing on Earth today.

There is an old saying - once you are in orbit you are halfway to anywhere in the solar system.

The delta V to achieve orbit is the killer, once in orbit that same delta V (if you could refuel) is enough to get you to just about anywhere in the solar system. It may take a few weeks, months or years. depending on how far the target is.

For TL7 setting building an orbital refueling station is a must, as is a moon base if you happen to have a nearby companion like we do here on Earth.

For combat in such a setting I would seriously consider going with quasi-vehicle combat scale since ships will be nowhere near as fast as gravitic maneuver drive ships with their near infinite delta V.